/*Done with <CTRL-SHIFT-L> template code
that was modified.

This is an advanced demo that shows
that you can place ctrls on the
wall paper.

See ::/Demo/Graphics/Slider.ZC
and ::/Demo/Graphics/WallPaperFish.ZC
before messing with this program.

It must be "System Included".
*/

#define SLIDER_RANGE    30
#define SLIDER_SPACING  20
#define SLIDER_BORDER   2

class CSliderState
{
    I64 left_pos;
    I64 right_pos;
};

U0 DrawCtrlSlider(CDC *dc, CCtrl *c)
{
    CSliderState *s = c->state;

    dc->color = LTRED;
    GrRect(dc,  c->left, c->top, SLIDER_SPACING * 3 + 2, SLIDER_SPACING * 2 + SLIDER_RANGE);
    dc->color = BLUE;
    GrRect(dc,  c->left + SLIDER_BORDER, c->top + SLIDER_BORDER, 
                SLIDER_SPACING * 3 + 2 - 2 * SLIDER_BORDER, 
                SLIDER_SPACING * 2 + SLIDER_RANGE - 2 * SLIDER_BORDER);
    dc->color = BLACK;
    GrLine(dc,  c->left + 1 * SLIDER_SPACING + 0, c->top + SLIDER_SPACING, 
                c->left + 1 * SLIDER_SPACING + 0, c->top + SLIDER_SPACING + SLIDER_RANGE - 1);

    GrLine(dc,  c->left + 2 * SLIDER_SPACING + 1, c->top + SLIDER_SPACING, 
                c->left + 2 * SLIDER_SPACING + 1, c->top + SLIDER_SPACING + SLIDER_RANGE - 1);
    dc->color = LTRED;
    GrPrint(dc, c->left + 1 * SLIDER_SPACING + 0 - FONT_WIDTH / 2, 
                c->top + SLIDER_SPACING + SLIDER_RANGE + 3, 
                "%d", s->left_pos * 10 / SLIDER_RANGE);
    GrPrint(dc, c->left + 2 * SLIDER_SPACING + 1 - FONT_WIDTH / 2, 
                c->top + SLIDER_SPACING + SLIDER_RANGE+3, 
                "%d", s->right_pos * 10 / SLIDER_RANGE);
    GrRect(dc,  c->left + 1 * SLIDER_SPACING + 0 - 3, 
                c->top + SLIDER_SPACING + SLIDER_RANGE - 1 - s->left_pos - 2, 7, 5);

    GrRect(dc,  c->left + 2 * SLIDER_SPACING + 1 - 3, 
                c->top + SLIDER_SPACING + SLIDER_RANGE - 1 - s->right_pos - 2, 7, 5);
    dc->color = YELLOW;
    GrRect(dc,  c->left + 1 * SLIDER_SPACING + 0 - 2, 
                c->top + SLIDER_SPACING + SLIDER_RANGE - 1 - s->left_pos - 1, 5, 3);

    GrRect(dc,  c->left + 2 * SLIDER_SPACING + 1 - 2, 
                c->top + SLIDER_SPACING + SLIDER_RANGE - 1 - s->right_pos - 1, 5, 3);
}

U0 UpdateDerivedCtrlSlider(CCtrl *c)
{
    CSliderState *s = c->state;

    c->left         = c->win_task->pix_width / 2 - (SLIDER_SPACING * 3 + 2) / 2;
    c->right        = c->left + 3 * SLIDER_SPACING + 2;
    c->top          = c->win_task->pix_height / 2 - (SLIDER_SPACING * 2 + SLIDER_RANGE) / 2;
    c->bottom       = c->top + SLIDER_SPACING * 2 + SLIDER_RANGE;
    s->left_pos     = ClampI64(s->left_pos, 0, SLIDER_RANGE   -1);
    s->right_pos    = ClampI64(s->right_pos, 0, SLIDER_RANGE  -1);
}

U0 LeftClickSlider(CCtrl *c, I64 x, I64 y, Bool)
{
    CSliderState *s = c->state;

    if (x < c->left + 1 * SLIDER_SPACING + 0 + SLIDER_SPACING / 2)
        s->left_pos  = SLIDER_RANGE - 1 - (y - (c->top + SLIDER_SPACING));
    else
        s->right_pos = SLIDER_RANGE - 1 - (y - (c->top + SLIDER_SPACING));
    if (c->update_derived_vals)
        (*c->update_derived_vals)(c);
}

CCtrl *SliderNew()
{
    CCtrl *c;

    if (Fs != sys_task)
    {
        "Must be System Included with SHIFT-F5.\n"
        "(Would crash when code mem was freed.)\n";
        return NULL;
    }
    c = SysCAlloc(sizeof(CCtrl));
    c->win_task             = sys_winmgr_task;
    c->flags                = CTRLF_SHOW | CTRLF_CAPTURE_LEFT_MS;
    c->type                 = CTRLT_GENERIC;
    c->state                = SysCAlloc(sizeof(CSliderState));
    c->draw_it              = &DrawCtrlSlider;
    c->left_click           = &LeftClickSlider;
    c->update_derived_vals  = &UpdateDerivedCtrlSlider;
    QueueInsert(c, sys_winmgr_task->last_ctrl);
    TaskDerivedValsUpdate;
    return c;
}

U0 SliderDel(CCtrl *c)
{
    QueueRemove(c);
    Free(c->state);
    Free(c);
}

SliderNew;